//
// CalendarView (for Prototype)
// calendarview.org
//
// Maintained by Justin Mecham <justin@aspect.net>
//
// Portions Copyright 2002-2005 Mihai Bazon
//
// This calendar is based very loosely on the Dynarch Calendar in that it was
// used as a base, but completely gutted and more or less rewritten in place
// to use the Prototype JavaScript library.
//
// As such, CalendarView is licensed under the terms of the GNU Lesser General
// Public License (LGPL). More information on the Dynarch Calendar can be
// found at:
//
//   www.dynarch.com/projects/calendar
//

var Calendar = Class.create()

//------------------------------------------------------------------------------
// Constants
//------------------------------------------------------------------------------

Calendar.VERSION = '1.2'

Calendar.DAY_NAMES = new Array(
  'Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday',
  'Sunday'
)

Calendar.SHORT_DAY_NAMES = new Array(
  'S', 'M', 'T', 'W', 'T', 'F', 'S', 'S'
)

Calendar.MONTH_NAMES = new Array(
  'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August',
  'September', 'October', 'November', 'December'
)

Calendar.SHORT_MONTH_NAMES = new Array(
  'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov',
  'Dec'
)

Calendar.NAV_PREVIOUS_YEAR = -2
Calendar.NAV_PREVIOUS_MONTH = -1
Calendar.NAV_TODAY = 0
Calendar.NAV_NEXT_MONTH = 1
Calendar.NAV_NEXT_YEAR = 2

//------------------------------------------------------------------------------
// Static Methods
//------------------------------------------------------------------------------

// This gets called when the user presses a mouse button anywhere in the
// document, if the calendar is shown. If the click was outside the open
// calendar this function closes it.
Calendar._checkCalendar = function (event) {
    if (!window._popupCalendar)
        return false
    if (Element.descendantOf(Event.element(event), window._popupCalendar.container))
        return
    window._popupCalendar.callCloseHandler()
    return Event.stop(event)
}

//------------------------------------------------------------------------------
// Event Handlers
//------------------------------------------------------------------------------

Calendar.handleMouseDownEvent = function (event) {
    Event.observe(document, 'mouseup', Calendar.handleMouseUpEvent)
    Event.stop(event)
}

// XXX I am not happy with how clicks of different actions are handled. Need to
// clean this up!
Calendar.handleMouseUpEvent = function (event) {
    var el = Event.element(event)
    var calendar = el.calendar
    var isNewDate = false

    // If the element that was clicked on does not have an associated Calendar
    // object, return as we have nothing to do.
    if (!calendar) return false

    // Clicked on a day
    if (typeof el.navAction == 'undefined') {
        if (calendar.currentDateElement) {
            Element.removeClassName(calendar.currentDateElement, 'selected')
            Element.addClassName(el, 'selected')
            calendar.shouldClose = (calendar.currentDateElement == el)
            if (!calendar.shouldClose) calendar.currentDateElement = el
        }
        calendar.date.setDateOnly(el.date)
        isNewDate = true
        calendar.shouldClose = !el.hasClassName('otherDay')
        var isOtherMonth = !calendar.shouldClose
        if (isOtherMonth) calendar.update(calendar.date)
    }

    // Clicked on an action button
    else {
        var date = new Date(calendar.date)

        if (el.navAction == Calendar.NAV_TODAY)
            date.setDateOnly(new Date())

        var year = date.getFullYear()
        var mon = date.getMonth()
        function setMonth(m) {
            var day = date.getDate()
            var max = date.getMonthDays(m)
            if (day > max) date.setDate(max)
            date.setMonth(m)
        }
        switch (el.navAction) {

            // Previous Year 
            case Calendar.NAV_PREVIOUS_YEAR:
                if (year > calendar.minYear)
                    date.setFullYear(year - 1)
                break

                // Previous Month
            case Calendar.NAV_PREVIOUS_MONTH:
                if (mon > 0) {
                    setMonth(mon - 1)
                }
                else if (year-- > calendar.minYear) {
                    date.setFullYear(year)
                    setMonth(11)
                }
                break

                // Today
            case Calendar.NAV_TODAY:
                break

                // Next Month
            case Calendar.NAV_NEXT_MONTH:
                if (mon < 11) {
                    setMonth(mon + 1)
                }
                else if (year < calendar.maxYear) {
                    date.setFullYear(year + 1)
                    setMonth(0)
                }
                break

                // Next Year
            case Calendar.NAV_NEXT_YEAR:
                if (year < calendar.maxYear)
                    date.setFullYear(year + 1)
                break

        }

        if (!date.equalsTo(calendar.date)) {
            calendar.setDate(date)
            isNewDate = true
        } else if (el.navAction == 0) {
            isNewDate = (calendar.shouldClose = true)
        }
    }

    if (isNewDate) event && calendar.callSelectHandler()
    if (calendar.shouldClose) event && calendar.callCloseHandler()

    Event.stopObserving(document, 'mouseup', Calendar.handleMouseUpEvent)

    return Event.stop(event)
}

Calendar.defaultSelectHandler = function (calendar) {
    if (!calendar.dateField) return false

    // Update dateField value
    if (calendar.dateField.tagName == 'DIV')
        Element.update(calendar.dateField, calendar.date.print(calendar.dateFormat))
    else if (calendar.dateField.tagName == 'INPUT') {
        calendar.dateField.value = calendar.date.print(calendar.dateFormat)
    }

    // Trigger the onchange callback on the dateField, if one has been defined
    if (typeof calendar.dateField.onchange == 'function')
        calendar.dateField.onchange()

    // Call the close handler, if necessary
    if (calendar.shouldClose) calendar.callCloseHandler()
}

Calendar.defaultCloseHandler = function (calendar) {
    calendar.hide()
}


//------------------------------------------------------------------------------
// Calendar Setup
//------------------------------------------------------------------------------

Calendar.setup = function (params) {

    function param_default(name, def) {
        if (!params[name]) params[name] = def
    }

    param_default('dateField', null)
    param_default('triggerElement', null)
    param_default('parentElement', null)
    param_default('selectHandler', null)
    param_default('closeHandler', null)

    // In-Page Calendar
    if (params.parentElement) {
        var calendar = new Calendar(params.parentElement)
        calendar.setSelectHandler(params.selectHandler || Calendar.defaultSelectHandler)
        if (params.dateFormat)
            calendar.setDateFormat(params.dateFormat)
        if (params.dateField) {
            calendar.setDateField(params.dateField)
            calendar.parseDate(calendar.dateField.innerHTML || calendar.dateField.value)
        }
        calendar.show()
        return calendar
    }

    // Popup Calendars
    //
    // XXX There is significant optimization to be had here by creating the
    // calendar and storing it on the page, but then you will have issues with
    // multiple calendars on the same page.
    else {
        var triggerElement = $(params.triggerElement || params.dateField)
        triggerElement.onclick = function () {
            var calendar = new Calendar()
            calendar.setSelectHandler(params.selectHandler || Calendar.defaultSelectHandler)
            calendar.setCloseHandler(params.closeHandler || Calendar.defaultCloseHandler)
            if (params.dateFormat)
                calendar.setDateFormat(params.dateFormat)
            if (params.dateField) {
                calendar.setDateField(params.dateField)
                calendar.parseDate(calendar.dateField.innerHTML || calendar.dateField.value)
            }
            if (params.dateField)
                Date.parseDate(calendar.dateField.value || calendar.dateField.innerHTML, calendar.dateFormat)
            calendar.showAtElement(triggerElement)
            return calendar
        }
    }

}



//------------------------------------------------------------------------------
// Calendar Instance
//------------------------------------------------------------------------------

Calendar.prototype = {

    // The HTML Container Element
    container: null,

    // Callbacks
    selectHandler: null,
    closeHandler: null,

    // Configuration
    minYear: 1900,
    maxYear: 2100,
    dateFormat: '%Y-%m-%d',

    // Dates
    date: new Date(),
    currentDateElement: null,

    // Status
    shouldClose: false,
    isPopup: true,

    dateField: null,


    //----------------------------------------------------------------------------
    // Initialize
    //----------------------------------------------------------------------------

    initialize: function (parent) {
        if (parent)
            this.create($(parent))
        else
            this.create()
    },



    //----------------------------------------------------------------------------
    // Update / (Re)initialize Calendar
    //----------------------------------------------------------------------------

    update: function (date) {
        var calendar = this
        var today = new Date()
        var thisYear = today.getFullYear()
        var thisMonth = today.getMonth()
        var thisDay = today.getDate()
        var month = date.getMonth();
        var dayOfMonth = date.getDate();

        // Ensure date is within the defined range
        if (date.getFullYear() < this.minYear)
            date.setFullYear(this.minYear)
        else if (date.getFullYear() > this.maxYear)
            date.setFullYear(this.maxYear)

        this.date = new Date(date)

        // Calculate the first day to display (including the previous month)
        date.setDate(1)
        date.setDate(-(date.getDay()) + 1)

        // Fill in the days of the month
        Element.getElementsBySelector(this.container, 'tbody tr').each(
      function (row, i) {
          var rowHasDays = false
          row.immediateDescendants().each(
          function (cell, j) {
              var day = date.getDate()
              var dayOfWeek = date.getDay()
              var isCurrentMonth = (date.getMonth() == month)

              // Reset classes on the cell
              cell.className = ''
              cell.date = new Date(date)
              cell.update(day)

              // Account for days of the month other than the current month
              if (!isCurrentMonth)
                  cell.addClassName('otherDay')
              else
                  rowHasDays = true

              // Ensure the current day is selected
              if (isCurrentMonth && day == dayOfMonth) {
                  cell.addClassName('selected')
                  calendar.currentDateElement = cell
              }

              // Today
              if (date.getFullYear() == thisYear && date.getMonth() == thisMonth && day == thisDay)
                  cell.addClassName('today')

              // Weekend
              if ([0, 6].indexOf(dayOfWeek) != -1)
                  cell.addClassName('weekend')

              // Set the date to tommorrow
              date.setDate(day + 1)
          }
        )
          // Hide the extra row if it contains only days from another month
          !rowHasDays ? row.hide() : row.show()
      }
    )

        this.container.getElementsBySelector('td.title')[0].update(
      Calendar.MONTH_NAMES[month] + ' ' + this.date.getFullYear()
    )
    },



    //----------------------------------------------------------------------------
    // Create/Draw the Calendar HTML Elements
    //----------------------------------------------------------------------------

    create: function (parent) {

        // If no parent was specified, assume that we are creating a popup calendar.
        if (!parent) {
            parent = document.getElementsByTagName('body')[0]
            this.isPopup = true
        } else {
            this.isPopup = false
        }

        // Calendar Table
        var table = new Element('table')

        // Calendar Header
        var thead = new Element('thead')
        table.appendChild(thead)

        // Title Placeholder
        var row = new Element('tr')
        var cell = new Element('td', { colSpan: 7 })
        cell.addClassName('title')
        row.appendChild(cell)
        thead.appendChild(row)

        // Calendar Navigation
        row = new Element('tr')
        this._drawButtonCell(row, '&#x00ab;', 1, Calendar.NAV_PREVIOUS_YEAR)
        this._drawButtonCell(row, '&#x2039;', 1, Calendar.NAV_PREVIOUS_MONTH)
        this._drawButtonCell(row, 'Today', 3, Calendar.NAV_TODAY)
        this._drawButtonCell(row, '&#x203a;', 1, Calendar.NAV_NEXT_MONTH)
        this._drawButtonCell(row, '&#x00bb;', 1, Calendar.NAV_NEXT_YEAR)
        thead.appendChild(row)

        // Day Names
        row = new Element('tr')
        for (var i = 0; i < 7; ++i) {
            cell = new Element('th').update(Calendar.SHORT_DAY_NAMES[i])
            if (i == 0 || i == 6)
                cell.addClassName('weekend')
            row.appendChild(cell)
        }
        thead.appendChild(row)

        // Calendar Days
        var tbody = table.appendChild(new Element('tbody'))
        for (i = 6; i > 0; --i) {
            row = tbody.appendChild(new Element('tr'))
            row.addClassName('days')
            for (var j = 7; j > 0; --j) {
                cell = row.appendChild(new Element('td'))
                cell.calendar = this
            }
        }

        // Calendar Container (div)
        this.container = new Element('div')
        this.container.addClassName('calendar')
        if (this.isPopup) {
            this.container.setStyle({ position: 'absolute', display: 'none' })
            this.container.addClassName('popup')
        }
        this.container.appendChild(table)

        // Initialize Calendar
        this.update(this.date)

        // Observe the container for mousedown events
        Event.observe(this.container, 'mousedown', Calendar.handleMouseDownEvent)

        // Append to parent element
        parent.appendChild(this.container)

    },

    _drawButtonCell: function (parent, text, colSpan, navAction) {
        var cell = new Element('td')
        if (colSpan > 1) cell.colSpan = colSpan
        cell.className = 'button'
        cell.calendar = this
        cell.navAction = navAction
        cell.innerHTML = text
        cell.unselectable = 'on' // IE
        parent.appendChild(cell)
        return cell
    },



    //------------------------------------------------------------------------------
    // Callbacks
    //------------------------------------------------------------------------------

    // Calls the Select Handler (if defined)
    callSelectHandler: function () {
        if (this.selectHandler)
            this.selectHandler(this, this.date.print(this.dateFormat))
    },

    // Calls the Close Handler (if defined)
    callCloseHandler: function () {
        if (this.closeHandler)
            this.closeHandler(this)
    },



    //------------------------------------------------------------------------------
    // Calendar Display Functions
    //------------------------------------------------------------------------------

    // Shows the Calendar
    show: function () {
        this.container.show()
        if (this.isPopup) {
            window._popupCalendar = this
            Event.observe(document, 'mousedown', Calendar._checkCalendar)
        }
    },

    // Shows the calendar at the given absolute position
    showAt: function (x, y) {
        this.container.setStyle({ left: x + 'px', top: y + 'px' })
        this.show()
    },

    // Shows the Calendar at the coordinates of the provided element
    showAtElement: function (element) {
        var pos = Position.cumulativeOffset(element)
        this.showAt(pos[0], pos[1])
    },

    // Hides the Calendar
    hide: function () {
        if (this.isPopup)
            Event.stopObserving(document, 'mousedown', Calendar._checkCalendar)
        this.container.hide()
    },



    //------------------------------------------------------------------------------
    // Miscellaneous
    //------------------------------------------------------------------------------

    // Tries to identify the date represented in a string.  If successful it also
    // calls this.setDate which moves the calendar to the given date.
    parseDate: function (str, format) {
        if (!format)
            format = this.dateFormat
        this.setDate(Date.parseDate(str, format))
    },



    //------------------------------------------------------------------------------
    // Getters/Setters
    //------------------------------------------------------------------------------

    setSelectHandler: function (selectHandler) {
        this.selectHandler = selectHandler
    },

    setCloseHandler: function (closeHandler) {
        this.closeHandler = closeHandler
    },

    setDate: function (date) {
        if (!date.equalsTo(this.date))
            this.update(date)
    },

    setDateFormat: function (format) {
        this.dateFormat = format
    },

    setDateField: function (field) {
        this.dateField = $(field)
    },

    setRange: function (minYear, maxYear) {
        this.minYear = minYear
        this.maxYear = maxYear
    }

}

// global object that remembers the calendar
window._popupCalendar = null





























//==============================================================================
//
// Date Object Patches
//
// This is pretty much untouched from the original. I really would like to get
// rid of these patches if at all possible and find a cleaner way of
// accomplishing the same things. It's a shame Prototype doesn't extend Date at
// all.
//
//==============================================================================

Date.DAYS_IN_MONTH = new Array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31)
Date.SECOND = 1000 /* milliseconds */
Date.MINUTE = 60 * Date.SECOND
Date.HOUR = 60 * Date.MINUTE
Date.DAY = 24 * Date.HOUR
Date.WEEK = 7 * Date.DAY

// Parses Date
Date.parseDate = function (str, fmt) {
    var today = new Date();
    var y = 0;
    var m = -1;
    var d = 0;
    var a = str.split(/\W+/);
    var b = fmt.match(/%./g);
    var i = 0, j = 0;
    var hr = 0;
    var min = 0;

    for (i = 0; i < a.length; ++i) {
        if (!a[i]) continue;
        switch (b[i]) {
            case "%d":
            case "%e":
                d = parseInt(a[i], 10);
                break;
            case "%m":
                m = parseInt(a[i], 10) - 1;
                break;
            case "%Y":
            case "%y":
                y = parseInt(a[i], 10);
                (y < 100) && (y += (y > 29) ? 1900 : 2000);
                break;
            case "%b":
            case "%B":
                for (j = 0; j < 12; ++j) {
                    if (Calendar.MONTH_NAMES[j].substr(0, a[i].length).toLowerCase() == a[i].toLowerCase()) {
                        m = j;
                        break;
                    }
                }
                break;
            case "%H":
            case "%I":
            case "%k":
            case "%l":
                hr = parseInt(a[i], 10);
                break;
            case "%P":
            case "%p":
                if (/pm/i.test(a[i]) && hr < 12)
                    hr += 12;
                else if (/am/i.test(a[i]) && hr >= 12)
                    hr -= 12;
                break;
            case "%M":
                min = parseInt(a[i], 10);
                break;
        }
    }
    if (isNaN(y)) y = today.getFullYear();
    if (isNaN(m)) m = today.getMonth();
    if (isNaN(d)) d = today.getDate();
    if (isNaN(hr)) hr = today.getHours();
    if (isNaN(min)) min = today.getMinutes();
    if (y != 0 && m != -1 && d != 0)
        return new Date(y, m, d, hr, min, 0);
    y = 0; m = -1; d = 0;
    for (i = 0; i < a.length; ++i) {
        if (a[i].search(/[a-zA-Z]+/) != -1) {
            var t = -1;
            for (j = 0; j < 12; ++j) {
                if (Calendar.MONTH_NAMES[j].substr(0, a[i].length).toLowerCase() == a[i].toLowerCase()) { t = j; break; }
            }
            if (t != -1) {
                if (m != -1) {
                    d = m + 1;
                }
                m = t;
            }
        } else if (parseInt(a[i], 10) <= 12 && m == -1) {
            m = a[i] - 1;
        } else if (parseInt(a[i], 10) > 31 && y == 0) {
            y = parseInt(a[i], 10);
            (y < 100) && (y += (y > 29) ? 1900 : 2000);
        } else if (d == 0) {
            d = a[i];
        }
    }
    if (y == 0)
        y = today.getFullYear();
    if (m != -1 && d != 0)
        return new Date(y, m, d, hr, min, 0);
    return today;
};

// Returns the number of days in the current month
Date.prototype.getMonthDays = function (month) {
    var year = this.getFullYear()
    if (typeof month == "undefined")
        month = this.getMonth()
    if (((0 == (year % 4)) && ((0 != (year % 100)) || (0 == (year % 400)))) && month == 1)
        return 29
    else
        return Date.DAYS_IN_MONTH[month]
};

// Returns the number of day in the year
Date.prototype.getDayOfYear = function () {
    var now = new Date(this.getFullYear(), this.getMonth(), this.getDate(), 0, 0, 0);
    var then = new Date(this.getFullYear(), 0, 0, 0, 0, 0);
    var time = now - then;
    return Math.floor(time / Date.DAY);
};

/** Returns the number of the week in year, as defined in ISO 8601. */
Date.prototype.getWeekNumber = function () {
    var d = new Date(this.getFullYear(), this.getMonth(), this.getDate(), 0, 0, 0);
    var DoW = d.getDay();
    d.setDate(d.getDate() - (DoW + 6) % 7 + 3); // Nearest Thu
    var ms = d.valueOf(); // GMT
    d.setMonth(0);
    d.setDate(4); // Thu in Week 1
    return Math.round((ms - d.valueOf()) / (7 * 864e5)) + 1;
};

/** Checks date and time equality */
Date.prototype.equalsTo = function (date) {
    return ((this.getFullYear() == date.getFullYear()) &&
   (this.getMonth() == date.getMonth()) &&
   (this.getDate() == date.getDate()) &&
   (this.getHours() == date.getHours()) &&
   (this.getMinutes() == date.getMinutes()));
};

/** Set only the year, month, date parts (keep existing time) */
Date.prototype.setDateOnly = function (date) {
    var tmp = new Date(date);
    this.setDate(1);
    this.setFullYear(tmp.getFullYear());
    this.setMonth(tmp.getMonth());
    this.setDate(tmp.getDate());
};

/** Prints the date in a string according to the given format. */
Date.prototype.print = function (str) {
    var m = this.getMonth();
    var d = this.getDate();
    var y = this.getFullYear();
    var wn = this.getWeekNumber();
    var w = this.getDay();
    var s = {};
    var hr = this.getHours();
    var pm = (hr >= 12);
    var ir = (pm) ? (hr - 12) : hr;
    var dy = this.getDayOfYear();
    if (ir == 0)
        ir = 12;
    var min = this.getMinutes();
    var sec = this.getSeconds();
    s["%a"] = Calendar.SHORT_DAY_NAMES[w]; // abbreviated weekday name [FIXME: I18N]
    s["%A"] = Calendar.DAY_NAMES[w]; // full weekday name
    s["%b"] = Calendar.SHORT_MONTH_NAMES[m]; // abbreviated month name [FIXME: I18N]
    s["%B"] = Calendar.MONTH_NAMES[m]; // full month name
    // FIXME: %c : preferred date and time representation for the current locale
    s["%C"] = 1 + Math.floor(y / 100); // the century number
    s["%d"] = (d < 10) ? ("0" + d) : d; // the day of the month (range 01 to 31)
    s["%e"] = d; // the day of the month (range 1 to 31)
    // FIXME: %D : american date style: %m/%d/%y
    // FIXME: %E, %F, %G, %g, %h (man strftime)
    s["%H"] = (hr < 10) ? ("0" + hr) : hr; // hour, range 00 to 23 (24h format)
    s["%I"] = (ir < 10) ? ("0" + ir) : ir; // hour, range 01 to 12 (12h format)
    s["%j"] = (dy < 100) ? ((dy < 10) ? ("00" + dy) : ("0" + dy)) : dy; // day of the year (range 001 to 366)
    s["%k"] = hr;   // hour, range 0 to 23 (24h format)
    s["%l"] = ir;   // hour, range 1 to 12 (12h format)
    s["%m"] = (m < 9) ? ("0" + (1 + m)) : (1 + m); // month, range 01 to 12
    s["%M"] = (min < 10) ? ("0" + min) : min; // minute, range 00 to 59
    s["%n"] = "\n";   // a newline character
    s["%p"] = pm ? "PM" : "AM";
    s["%P"] = pm ? "pm" : "am";
    // FIXME: %r : the time in am/pm notation %I:%M:%S %p
    // FIXME: %R : the time in 24-hour notation %H:%M
    s["%s"] = Math.floor(this.getTime() / 1000);
    s["%S"] = (sec < 10) ? ("0" + sec) : sec; // seconds, range 00 to 59
    s["%t"] = "\t";   // a tab character
    // FIXME: %T : the time in 24-hour notation (%H:%M:%S)
    s["%U"] = s["%W"] = s["%V"] = (wn < 10) ? ("0" + wn) : wn;
    s["%u"] = w + 1;  // the day of the week (range 1 to 7, 1 = MON)
    s["%w"] = w;    // the day of the week (range 0 to 6, 0 = SUN)
    // FIXME: %x : preferred date representation for the current locale without the time
    // FIXME: %X : preferred time representation for the current locale without the date
    s["%y"] = ('' + y).substr(2, 2); // year without the century (range 00 to 99)
    s["%Y"] = y;    // year with the century
    s["%%"] = "%";    // a literal '%' character

    return str.gsub(/%./, function (match) { return s[match] || match });
};

Date.prototype.__msh_oldSetFullYear = Date.prototype.setFullYear;
Date.prototype.setFullYear = function (y) {
    var d = new Date(this);
    d.__msh_oldSetFullYear(y);
    if (d.getMonth() != this.getMonth())
        this.setDate(28);
    this.__msh_oldSetFullYear(y);
}